T wave abnormalities

Peaked T waves

Tall, narrow, symmetrically peaked T-waves are characteristically seen in hyperkalaemia.

Peaked T waves due to hyperkalaemia

Hyperacute T waves

Broad, asymmetrically peaked or ‘hyperacute’ T-waves are seen in the early stages of ST-elevation MI (STEMI) and often precede the appearance of ST elevation and Q waves. They are also seen with Prinzmetal angina.

Hyperacute T waves due to anterior STEMI

Loss of precordial T-wave balance

Loss of precordial T-wave imbalance occurs when the upright T wave is larger than that in V6. This is a type of hyperacute T wave.

The normal T wave in V1 is inverted. An upright T wave in V1 is considered abnormal — especially if it is tall (TTV1), and especially if it is new (NTTV1).

This finding indicates a high likelihood of coronary artery disease, and when new implies acute ischemia.

Inverted T waves

Inverted T waves are seen in the following conditions:

Normal finding in children

Persistent juvenile T wave pattern

Myocardial ischaemia and infarction

Bundle branch block

Ventricular hypertrophy (‘strain’ patterns)

Pulmonary embolism

Hypertrophic cardiomyopathy

Raised intracranial pressure

T wave inversion in lead III is a normal variant. New T-wave inversion (compared with prior ECGs) is always abnormal. Pathological T wave inversion is usually symmetrical and deep (>3mm).

Paediatric T waves

Inverted T-waves in the right precordial leads (V1-3) are a normal finding in children, representing the dominance of right ventricular forces.

Normal pattern of T-wave inversions in a 2-year old boy

Persistent Juvenile T-wave Pattern

T-wave inversions in the right precordial leads may persist into adulthood and are most commonly seen in young Afro-Caribbean women. Persistent juvenile T-waves are asymmetric, shallow (<3mm) and usually limited to leads V1-3.

Persistent juvenile T-waves in an adult

Myocardial Ischaemia and Infarction

T-wave inversions due to myocardial ischaemia or infarction occur in contiguousleads based on the anatomical location of the area of ischaemia/infarction:

Inferior = II, III, aVF

Lateral = I, aVL, V5-6

Anterior = V2-6

NOTE:

Dynamic T-wave inversions are seen with acute myocardial ischaemia.

Fixed T-wave inversions are seen following infarction, usually in association with pathological Q waves.

Wellens’ Syndrome

Wellens’ syndrome is a pattern of inverted or biphasic T waves in V2-3 (in patients presenting with ischaemic chest pain) that is highly specific for critical stenosis of the left anterior descending artery.

There are two patterns of T-wave abnormality in Wellens’ syndrome:

Type 1 Wellens’ T-waves are deeply and symmetrically inverted

Type 2 Wellens’ T-waves are biphasic, with the initial deflection positive and the terminal deflection negative

Wellens’ Type 1

Wellens’ Type 2

‘Camel hump’ T waves

This is a term used by the great ECG lecturer and Emergency Physician Amal Mattu to describe T-waves that have a double peak or ‘camel hump’ appearance.

There are two causes for camel hump T waves:

Prominent U waves fused to the end of the T wave, as seen in severe hypokalaemia

Hidden P waves embedded in the T wave, as seen in sinus tachycardia and various types of heart block

About Edward Burns

Ed Burns is an Emergency Physician working in Prehospital & Retrieval Medicine in Sydney, Australia. He has a passion for ECG interpretation and medical education. Ed is the force behind the LITFL ECG library | + Edward Burns | @edjamesburns

LITFL is a medical blog and website dedicated to providing free online emergency medicine and critical care insights and education for everyone, everywhere...anytime. Our Team, headed by Mike Cadogan & Chris Nickson, consists (mostly) of emergency physicians and intensivists based in Australia and New Zealand.

We invite you to use our content in anyway to help others learn, all we ask is that you spread the word about the FOAM (Free Open Access Meducation) revolution...and get #FOAMed !